The present invention relates to large area cathodoluminescent image display devices having a plurality of cathode stripes; and particularly to systems for addressing the cathode stripes.
Flat large area cathodoluminescent display devices have been suggested for use in image displays, such as television. These devices may have a matrix of individually addressable electron sources formed by electron multipliers operating in a regenerative feedback mode. Such devices have a plurality of cathode stripes at one end of an electron multiplier and a cathodoluminescent screen at the other end. The electrons from the cathodes enter the multiplier, which amplifies the electron flow. Modulating, focussing and accelerating electrodes are between the multiplier and the screen to shape the electron beam and accelerate it toward the screen which is coated with phosphor material to emit light upon electron bombardment. The output of the electron multiplier also generates a feedback species, such as positive gas ions. These positive ions in the display device travel back to and strike the cathodes thereby emitting secondary electrons and completing a feedback loop so as to allow sustained electron emission.
Each of the cathode stripes is used to address a line in the image display. Particular image elements along each line are selected by addressing various electron multipliers. Therefore, in order to display a particular element on the screen, the corresponding cathode stripe and the electron multiplier must be activated. If the display device is to be used for a conventional NTSC television display, it must have a minimum of 483 cathode stripes for displaying the equivalent number of display lines. This results in a large number of electrical feedthroughs in the display envelope in order to address each of the cathodes individually as well as a complex circuit for addressing each of the stripes.